Catalyst unit

ABSTRACT

A catalyst unit may include a carrier that channels may be formed from a front surface thereof to a rear surface thereof, and plugs that closes the channels that may be formed along an edge portion of the front surface except a central portion of the front surface, wherein a coating layer may be not formed in the channels that the plugs may be disposed and a coating layer may be formed along the remaining opened channels.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2011-0045177 filed in the Korean Intellectual Property Office on May13, 2011, the entire contents of which is incorporated herein for allpurposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a catalyst unit that includes catalystingredients to reduce harmful materials of exhaust gas according to aflow characteristic.

2. Description of Related Art

In a vehicle, a three way catalyst converter is generally used to purifyexhaust gas, which is disposed on an exhaust pipe, and thespecifications thereof are different, because exhaust gas flow rates aredifferent according to vehicles.

The three way catalytic converter simultaneously reacts harmfulmaterials of exhaust gas such as carbon monoxide, nitrogen oxide, andhydrocarbon compound to eliminate these materials, and mainly Pt/Rh,Pd/Rh or Pt/Pd/Rh series is formed in the three way catalytic converter.

Meanwhile, a diesel vehicle that generates large amount of noxiousexhaust gas is excellent in a fuel consumption efficiency and a poweroutput, but nitrogen oxide and PM (particulate matters) are heavilyincluded therein in contrast to a gasoline vehicle.

In the diesel vehicle like this, because intake air is sufficientlycombusted in the most of driving condition, carbon monoxide andhydrocarbon is very little compared to the gasoline vehicle and nitrogenoxide and PM is heavily exhausted.

Recently, as a post process art, a diesel particulate filter research isvery actively being undergone so as to correspond to the reinforcedexhaust gas standard of the diesel vehicle, and there are many partsthat are to be developed so as to apply the diesel particulate filter toa real vehicle.

Platinum is used in a coating layer of a Diesel Oxidation Catalyst(DOC), separately, Diesel Particulate Filter (DPF) is applied to asystem of DOC+DPF, and CPF, which is recently being mass produced in aEU vehicle maker, and the reliability thereof increased the sales of thesystem.

And, a diesel particulate filter that a catalyst is coated thereon,which is called a diesel catalyzed particulate filter, has beendeveloped. Meanwhile, several methods have been widely known for coatingdifferent kinds of catalyst on a cordierite carrier, and there are manyprior arts.

For example, there is a dipping method that a cordierite carrier isdipped into catalyst solutions respectively having differentconcentrations and there is a suction method that one end side of acarrier is dipped into a catalyst solution and a vacuum pressure isformed in the other end side of the carrier to suck the catalystsolution through channels of the carrier.

However, these methods can be applied to a wall flow type of a carrier,and more particularly, different kinds coatings can be only applied to acarrier having the wall flow type, wherein CO or HC flows into an inletof a channel of the carrier to get out of the outlet thereof.

Meanwhile, a noble metal is coated in the whole carrier regardless offlow characteristic of exhaust gas when manufacturing the catalystcarrier, wherein there is a problem that a noble metal is notefficiently used according to the flow characteristic of the exhaustgas.

The information disclosed in this Background of the Invention section isonly for enhancement of understanding of the general background of theinvention and should not be taken as an acknowledgement or any form ofsuggestion that this information forms the prior art already known to aperson skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to provide acatalyst unit having advantages of decreasing a manufacturing cost bysaving a noble metal.

In an aspect of the present invention, the catalyst unit may include acarrier that channels are formed from a front surface thereof to a rearsurface thereof, and plugs that closes the channels that are formedalong an edge portion of the front surface except a central portion ofthe front surface, wherein a coating layer is not formed in the channelsthat the plugs are disposed and a coating layer is formed along theremaining opened channels.

The opened channels that the plugs are not formed thereon may have aninlet and an outlet that are opened, and exhaust gas flows into theinlet and flows out of the outlet.

An outlet of the channels that inlets thereof are closed by the plugs isclosed by plugs.

In another aspect of the present invention, a manufacturing method of acatalyst unit, may include extruding a carrier that channels are formedtherein from a front surface to a rear surface, plugging channels thatare formed along an edge portion of the front surface by plugs, andcoating catalyst along opened channels that are not plugged by theplugs.

The front surface of the carrier is dipped into a catalyst solution,which is wash coat, and the catalyst solution is sucked from the rearsurface of the carrier through the opened channels such that thecatalyst solution coats along an interior surface of the opened channelsin the process for coating the catalyst solution.

In further another aspect of the present invention, an exhaust gaspurification device may include an exhaust line that exhaust gas passestherethrough, a converter housing being disposed on the exhaust line andhaving a converter cone portion formed near the exhaust line, a catalystunit that is disposed within the converter housing and reduces harmfulmaterial of the exhaust gas, wherein an inlet of channels in thecatalyst unit that is formed near the converter cone portion is closedby plugs to form closed channels, coating layer is not formed along theclosed channels, and coating layer is formed along an interior surfaceof remained opened channels.

A diameter of the converter cone portion may be larger than that of theexhaust line.

As stated above, in the catalyst unit according to the presentinvention, the channels that are formed correspondingly to dead zonethat exhaust gas flow is low are closed by plugs and the catalystcoating layer is not formed along the interior surface of the closedchannels. Accordingly, the cost of the catalyst can he saved, and thepurification rate of the exhaust gas is securely maintained by closingthe channels that the exhaust gas flow is less.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description, which together serve to explaincertain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a catalyst unit according toan exemplary embodiment of the present invention.

FIG. 2 is a flowchart showing a manufacturing method of a catalyst unitaccording to an exemplary embodiment of the present invention.

FIG. 3 is a schematic cross sectional side view showing a method forcoating catalyst in a catalyst unit according to an exemplary embodimentof the present invention.

FIG. 4 is a cross sectional side view showing a condition that acatalyst unit is disposed according to an exemplary embodiment of thepresent invention.

It should be understood that the appended drawings are not necessarilyto scale, presenting a somewhat simplified representation of variousfeatures illustrative of the basic principles of the invention. Thespecific design features of the present invention as disclosed herein,including, for example, specific dimensions, orientations, locations,and shapes will be determined in part by the particular intendedapplication and use environment.

In the figures, reference numbers refer to the same or equivalent partsof the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments, it will beunderstood that the present description is not intended to limit theinvention(s) to those exemplary embodiments. On the contrary, theinvention(s) is/are intended to cover not only the exemplaryembodiments, but also various alternatives, modifications, equivalentsand other embodiments, which may be included within the spirit and scopeof the invention as defined by the appended claims.

An exemplary embodiment of the present invention will hereinafter bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view of a catalyst unit according toan exemplary embodiment of the present invention.

Referring to FIG. 1, channels are formed from the front surface to therear surface of the catalyst unit 100, wherein the channels includesopened channels 110 and closed channels 120. In an exemplary embodimentof the present invention, the catalyst unit 100 can be called ‘carrier’.

More particularly, the channels that are formed on an edge portion alonga circumference of the catalyst unit 100 are closed by plugs to form theclosed channels 120, and the opened channels 110 are formed in a centralportion.

The inlets and the outlets of the closed channels 120 are closed by theplugs 122 and the catalyst coating layers are not formed along theinterior surface of the closed channels. However, the catalyst coatinglayer 114 is formed along the interior surface of the opened channels110, as shown.

The exhaust gas flows through the opened channels that are formed in acentral portion of the catalyst unit 100, and the exhaust gas hardlyflows an edge portion of the catalyst unit 100. Accordingly, the edgeportion that the exhaust gas hardly flows is closed by the plugs 122 andthe catalyst layer is not formed therein such that the waste of theunnecessary catalyst is reduced.

The opened channel 110 has a flow through type that the inlet and theoutlet are opened, and the catalyst unit 100 can be made up ofcordierite material.

FIG. 2 is a flowchart showing a manufacturing method of a catalyst unitaccording to an exemplary embodiment of the present invention.

Referring to FIG. 2, in a S200, the catalyst unit 100 (hereinafter,carrier) is extruded. In this case, the opened channels aresimultaneously formed from the front surface to the rear surface of thecarrier 100.

After the carrier is extruded to be made, in a S210, the inlet of theedge channel is plugged by the plug 122.

If the plugging is completed, in a 5220, the opened channels 110 thatare not plugged by the plug 122 is coated by the catalyst coating layer114.

FIG. 3 is a schematic cross sectional side view showing a method forcoating catalyst in a catalyst unit according to an exemplary embodimentof the present invention.

Referring to FIG. 3, in a condition that the edge channels of the frontside or the rear side of the catalyst unit 100 is closed by the plug122, the front side of the catalyst unit 100 is dipped into catalystsolution 300, which is wash coat.

And, the suction device 310 that is disposed on the rear side of thecatalyst unit 100 is used to suck the catalyst solution 300 through theopened channels 110, and the catalyst coating layer 114 is formed alongthe interior surface of the opened channels 110.

Accordingly, the catalyst coating layer is not formed along the interiorsurface of the closed channels 120 that are formed in an edge portionsuch that the catalyst usage amount is reduced to save the productioncost. Further, since the exhaust gas hardly flow the edge portion exceptthe central portion of the front surface of the catalyst unit 100, thepurification rate hardly decreases.

FIG. 4 is a cross sectional side view showing a condition that acatalyst unit is disposed according to an exemplary embodiment of thepresent invention.

Referring to FIG. 4, a converter housing 430 is disposed on the exhaustline and the catalyst unit 100, carrier, is disposed within theconverter housing 430.

As shown, a converter cone portion 420 that the interior diameterthereof becomes wider is formed on the converter housing 430 near theexhaust line 400, and an edge portion of the catalyst unit 100 issupported by a portion of the converter cone portion 420.

Accordingly, a dead zone 410 is formed in a part of the catalyst unit100 corresponding to the converter cone portion 420, wherein the exhaustgas hardly flows the dead zone.

In an exemplary embodiment of the present invention, the inlet or theoutlet of the channels that are formed around a edge portion of thecarrier 100 corresponding to the dead zone 410 are closed by the plug122 and the coating layer is not formed in the closed channels.Accordingly, the purification rate of the exhaust gas is not bedeteriorated and the catalyst elements is efficiently used.

For convenience in explanation and accurate definition in the appendedclaims, the terms “interior” and “exterior” are used to describefeatures of the exemplary embodiments with reference to the positions ofsuch features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable others skilled in the art to make andutilize various exemplary embodiments of the present invention, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the invention be defined by the Claims appended hereto andtheir equivalents.

1. A catalyst unit, comprising: a carrier that channels are formed froma front surface thereof to a rear surface thereof; and plugs that closesthe channels that are formed along an edge portion of the front surfaceexcept a central portion of the front surface, wherein a coating layeris not formed in the channels that the plugs are disposed and a coatinglayer is formed along the remaining opened channels.
 2. The catalystunit of claim 1, wherein the opened channels that the plugs are notformed thereon have an inlet and an outlet that are opened, and exhaustgas flows into the inlet and flows out of the outlet.
 3. The catalystunit of claim 1, wherein an outlet of the channels that inlets thereofare closed by the plugs are closed by plugs.
 4. A manufacturing methodof a catalyst unit, comprising: extruding a carrier that channels areformed therein from a front surface to a rear surface; plugging channelsthat are formed along an edge portion of the front surface by plugs; andcoating catalyst along opened channels that are not plugged by theplugs.
 5. The manufacturing method of a catalyst unit of claim 4,wherein the front surface of the carrier is dipped into a catalystsolution, which is wash coat, and the catalyst solution is sucked fromthe rear surface of the carrier through the opened channels such thatthe catalyst solution coats along an interior surface of the openedchannels in the process for coating the catalyst solution.
 6. An exhaustgas purification device, comprising: an exhaust line that exhaust gaspasses therethrough; a converter housing being disposed on the exhaustline and having a converter cone portion formed near the exhaust line; acatalyst unit that is disposed within the converter housing and reducesharmful material of the exhaust gas, wherein an inlet of channels in thecatalyst unit that is formed near the converter cone portion is closedby plugs to form closed channels, coating layer is not formed along theclosed channels, and coating layer is formed along an interior surfaceof remained opened channels.
 7. The exhaust gas purification device ofclaim 6, wherein a diameter of the converter cone portion is larger thanthat of the exhaust line.